As a counter argument to this, for example when I play chess sometimes I feel that the 'holding of objects in working memory,' the "playing card castle" practice of thinking ahead that I build up in my head, has some practical use in the real world, but if I'm honest about it I feel the extremity and specificity of the scenario of chess is not transferable to the real world.
I think the argument that chess has improved my underlying hardware sounds reasonable, but it's also necessary that hardware be able to adapt to different scenarios in life. If I spend too much time on chess, it feels like that would end in a place where that hardware would be specifically tailored to just playing chess.
The strategy and also the heuristics that it teaches you are valuable, I can certainly agree with that. When you start playing a lot of chess, well at least I find that the incremental improvements you can make, after a while of playing, becomes a very narrow set of problems you are solving: mainly, how much can you "hold in your head" in terms of thinking ahead. That involves how well you can visualize the board.
I just found at a point getting better meant memorizing a lot of opening game theory, as well as memorizing end game tactics. Then, I'd probably still never be world class because I don't think I'm exceptional at visualizing chess piece movements--I may be better than 99% of all people but the way the top 1% of chess players can do it is just phenomenal. I feel like it's a specific skill that some people just have and get extremely good at. You really need to spend some time playing the game and getting better and better to realize how good at visualizing the ability to think ahead the top players are. Magnus Carlsen never studied chess using a board -- it is just natural for him to think about.
I think the argument that chess has improved my underlying hardware sounds reasonable, but it's also necessary that hardware be able to adapt to different scenarios in life. If I spend too much time on chess, it feels like that would end in a place where that hardware would be specifically tailored to just playing chess.